while attacking a pirate hideout i noticed the missiongiver NPC in their tavern
http://imageshack.us/f/20/pr3hideoutnpc.jpg/
that game me idea maybe for a DLC or for mod
if you have less than 5% reputation with all nations - you should be able to enter pirate hideout for selling the loot and ships repairs , and when reputation goes to 25% with any nation you will automatically lose access to hideouts - that should force you to keep attacking traders to keep rep low
of course this should not to be abused just for detecting hideouts
maybe one special hideout should appear when needed , and disappear upon losing access
it should add nice pirate life angle to this great game.